Prowirl 72 Simulated Current Output Overview
Prowirl 72 is a vortex flowmeter launched by Endress+Hauser, widely used for flow measurement of steam, gases, and liquids. Its simulated current output function allows the instrument to manually output a set 4-20mA current signal without relying on actual flow.
This function is mainly used for loop calibration, host computer signal testing, and troubleshooting, and is a practical tool for on-site commissioning and maintenance.
Main Uses of Simulated Current Output
On engineering sites, simulated current output can replace the real flow signal and help technicians independently verify the signal chain.
- Loop calibration: Verify whether the 4-20mA loop from the transmitter to the PLC/DCS is accurate.
- Troubleshooting: Distinguish whether the problem is with the instrument measurement or the downstream receiving end.
- System integration testing: Test host computer display and alarm logic when there is no actual flow.
- Regular maintenance: Confirm whether the current output accuracy meets process requirements.
Operation Steps
Entering Simulation Mode
- Ensure that the instrument is in measurement mode and is powered on.
- Enter the function menu through the local display or configuration software.
- Select the "Simulation" option.
- Enter the target current value (such as 4mA, 12mA, 20mA).
Exiting Simulation Mode
- After completing calibration, return to the simulation menu.
- Select "Exit Simulation".
- Confirm that the instrument returns to the actual flow output state.
Common Output Values and Corresponding Flow
The table below lists the correspondence between standard 4-20mA output and flow percentage for quick judgment.
| Output Current | Flow Percentage | Typical Use |
|---|---|---|
| 4 mA | 0% | Zero point calibration |
| 8 mA | 25% | Low flow test |
| 12 mA | 50% | Midpoint calibration |
| 16 mA | 75% | High flow test |
| 20 mA | 100% | Full scale calibration |
Precautions
- During simulation, the instrument will not respond to actual flow, so process safety must be confirmed.
- Some versions require entering an authorization password to enter simulation mode.
- After calibration is completed, be sure to exit simulation to avoid affecting normal measurement.
- If the output deviation is large, it is recommended to check the loop load and wiring.
Summary
Prowirl 72 simulated current output is an efficient tool for on-site commissioning and maintenance and can quickly verify the 4-20mA loop. Mastering its operation steps and precautions helps improve the reliability and maintenance efficiency of the instrument system.